comments on classification data turtles

[VladimirAlexiev]

http://semstats.org/2016/challenge/semstats-2016-challenge-data-v2.7z

nacer2.ttl

• nacer2 doesn't naturally parse to NACE r2 so I'd use a dash (in file name and URLs): nace-r2
• define and use @base and prefixes to shorten all URLs. Almost no absolute URL should remain in the file. This is a great way to check consistency between URLs and make it more useful for consumers. With a bit of URL tweaking, we can get to the much nicer:

@prefix nace-r2: <http://stamina-project.org/codes/nacer2/>.
@prefix nace-r2-section: <http://stamina-project.org/codes/nacer2/section/>.
@prefix nace-r2-division: <http://stamina-project.org/codes/nacer2/division/>.

nace-r2-section:A
        a                     skos:Concept ;
        xkos:coreContentNote  nace-r2-section:A-CentralContent ;
        skos:inScheme         nace-r2: ;
        skos:narrower         nace-r2-division:03 , nace-r2-division:02 , nace-r2-division:01 ;
        skos:notation         "A"^^nace-r2: ;
        skos:prefLabel        "AGRICULTURE, FORESTRY AND FISHING"@en ;
        skos:topConceptOf     nace-r2: .

• xkos:notationPattern maybe needs an anchored regexp ^...$ to validate the complete value. This is unclear, see below
• <nacer2/concept/section> is not defined
• all skos:notation use datatype ^^xsd:token
  • This satisfies the formal requirement in SKOS Reference "By convention, skos:notation is only used with typed literals".
  • However, it fails the implicit need of identifying what the code means, and the examples in SKOS Reference and SKOS Core that use a specific datatype
  • for this file, it's better to use a datatype like ^^nace-r2:. This identifies the codes as belonging to NACE r2

http://rdf-vocabulary.ddialliance.org/xkos

• clarify whether xkos:notationPattern is implicitly anchored. This is unclear from its label code pattern and the two pieces of info below
• Move ttl comments into rdfs:comment. Eg for xkos:notationPattern:

   rdfs:comment "Structure (defined as a regular expression) of the item codes at a given level"

• http://rdf-vocabulary.ddialliance.org/xkos.html says "should contain a regular expression refecting the code structure"